1. Field of the Invention
This invention relates generally to the concurrent control of a xerographic reproduction machine and an internal modem within the xerographic reproduction system for the purpose of allowing external communications with a remote system while simultaneously providing full feature reproduction capability.
2. Description of the Prior Art
It is a generally known technique to incorporate a modem into office equipment or systems for the purpose of enabling direct communications with external or remote devices. It is, however, usually necessary that the equipment or systems incorporating the communication capability operate in a less than fully functional state in order to initiate and maintain communications with the remote devices. Unfortunately, this requirement may severely limit the functionality of the office equipment or systems during the communication sessions, thereby reducing the throughput or features available for the systems.
In order to improve the performance of systems incorporating such communicating capability, it is a widely used practice to reserve actual data communication sessions for off-peak usage times when reductions in system functionality or throughput will not adversely affect system operation. This delayed data communication concept has been widely used in facsimile systems not only to maximize operator efficiency, but also to take advantage of lower data transmission charges during certain periods of the day.
For example, U.S. Pat. No. 4,646,160 to lizuka et al discloses a facsimile apparatus for transmitting/receiving image data. A first memory stores image data and a second memory stores external apparatus number and time data. Upon coincidence of stored time data and a time signal from a clock, the apparatus starts an automatic dialing mode to connect a line with an external apparatus.
The prior art also discloses means for recognizing and rectifying a fault within systems utilizing a modem for external communications. U.S. Pat. No. 4,112,467 to Ogawa discloses a failure mode control apparatus for electronic graphic data transmission systems. Failure or malfunction sensors are provided at the transmitter and receiver of facsimile machines to generate failure signals having the same frequency as a telephone network busy signal upon detection of a malfunction. Both the transmitter and receiver are reset at high speed to an initial ready for transmission status upon reception of a failure signal from either sensor and automatically disconnect from the telephone network.
U.S. Pat. No. 4,686,526 to Gritzo discloses a remote reset circuit which acts as a monitor and controller by clocking all characters sent by a terminal to a computer and comparing them to a reference character. When a match occurs, the remote reset circuit activates the system's hardware reset line. The reset circuit is hardware oriented and does not require software configuration or initialization.
U.S. Pat. No. 4,811,358 to Smedley et al. discloses a subscriber line interface modem for use in a telecommunication system. The modem comprises a bus interfacing means, channel means and clock supply means. The interface receives address data and control information from a microprocessor and dispatches information to the microprocessor for evaluation. The processing of information through the modem is controlled by a microprocessor in conjunction with clock signals generated by a clock supply means. The modem may be reset from three sources; a reset input, a software reset, and an individual channel reset.
The teachings of the prior art are focussed primarily on apparatus for providing external communications via a modem or similar means. The prior art also discloses examples of single function systems that utilize such means for external communication. However, the prior art does not disclose a means for external communications within a multi-function xerographic system. More specifically, the prior art does not disclose systems having multiple functions, including external communication capabilities, where the non-communication capabilities of the system are fully maintained during a communications session. It would be desirable, therefore, to provide a simultaneous capability of total multi-function operation and modem communication within a reproduction machine.
It is therefore, an object of the present invention to incorporate the capability for external communications into a multi-function, xerographic reproduction machine. It is a further object of the present invention to operate a modem, or similar external communication means, within a xerographic system in a concurrent fashion so as to avoid any interference with the normal reprographic functionality of the system. It is an additional object of the present invention to provide a method of resetting the external communication means when a fault state is detected without interruption of system reprographic functionality. It is a final objective of the present invention to enable the establishment of a remote communications link either as an initiator or as a receiver for the purpose of remote interactive communications (RIC) with a host computer or similar device and upon the termination of such a link, to cause the orderly shutdown of the entire reprographic machine to a power off state.
Further advantages of the present invention will become apparent as the following description proceeds and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.